With the increasing power of consumer electronics, the capacity of a battery pack applied in such consumer electronics is also increasing. Typically, a battery pack with a relatively large capacity may include several batteries. Thus, different batteries should be balanced during the operation process, in order to improve the utilization factor of the batteries. In addition, some of the batteries should be protected against being over-charged or over-discharged, as it may shorten the battery lifetime. In one approach, balancing battery power may be performed based on a voltage or a state of charge (SOC), but may not take the battery temperature into consideration. Thus aging of the lifetime of the battery may be accelerated as the battery temperature exceeds the normal operating temperature.